So they introduced the "divine controller" class that supposedly has a bunch of summoning powers (though there's only 1 out of the first 3 levels). Which in many ways is like the Favored Soul and maybe a bit of the Truenamer, where they use Words of Creation to call the Chains of Carceri, Sun Strikes and Purging Flames.
But the interesting part about Invokers is that while most of them worship the Gods, they draw upon a portion of the same divine powers from the same source that the Gods do, unlike the other divine classes who call upon faith through investiture. In terms of Planescape it probably means that an Athar or Godsmen Divine character is more likely to be an Invoker than a Cleric, Paladin or Avenger. They would certainly be calling on the Great Unknown or the Source in terms of the Godsmen.
Sounds like a fascinating class, though I don't have subscription to look at it.
What's the class features like? Something that complements summoning powers, I presume?